Evaluation of morphological and physiological plasticity in green coccoid microalgae grown in different pH and temperatures and their implications on species delimitation

• Grant number: 19/00231-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2019
• End date: August 31, 2020
• Field of knowledge: Biological Sciences - Botany - Plant Taxonomy
• Principal Investigator: Inessa Lacativa Bagatini
• Grantee: Ana Beatriz Janduzzo Amaro de Lima
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

The coccoid green microalgae have great ecological and biotechnological importance. They are quite diverse, and most have a simple morphology, and present morphological convergence and phenotypic plasticity that difficult their correct identification. Even molecular analyzes have been inefficient for this purpose, due to the incongruity and/or difficulty on the delimitation of phylogenetic and morphological species. In addition, some groups as the coccoid microalgae from the Selenastraceae family do not have sexual reproduction, making it impossible to use the biological concept of species. Thus, recent studies have proposed an integrative and multidisciplinary taxonomic approach, incorporating multiple species concepts (e.g., morphological, phylogenetic, ecological and physiological) in order to classify green microalgae more naturally. Morphological analysis, although very useful and widely used, should consider phenotypic plasticity in relation to abiotic environmental variations and contact with other organisms, which may lead to an erroneous identification and classification. Therefore, this project aims to analyze how seven strains of microalgae of the genus Ankistrodesmus behave in media with different pH and temperature conditions, evaluating the presence of morphological and physiological plasticity. We will measure length width, curvature and cellular biovolume and area, and growth rate of the microalgae in the different treatments. Besides that, we intend to relate these possible variations with their phylogenetic proximity, contributing to the study of species delimitation in the genus. This study will also allow the evaluation of experimental conditions that could be applied to asexual green microalgae to help on studies of species delimitation.